We are evaluating the effectiveness of an antimetabolic agent, termed "antabalone" found in the brains of hibernating ground squirrels (Citellus tridecemlineatus), in limiting myocardial damage due to hypoxia by use of the isolated, perfused, rat heart. Attempts at isolation of antabalone are being made using a cell culture assay. In addition, antabalone's effects on the whole rat via an intracerebral injection are being studied.